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Reviewed March 2010

What is the official name of the HESX1 gene?

The official name of this gene is “HESX homeobox 1.”

HESX1 is the gene's official symbol. The HESX1 gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the HESX1 gene?

The HESX1 gene provides instructions for producing a protein that regulates the activity of other genes. On the basis of this action, the HESX1 protein is called a transcription factor. The HESX1 gene is part of a family of homeobox genes, which act during early embryonic development to control the formation of many body structures.

The HESX1 protein plays an important role in early brain development. In particular, it is essential for the formation of the pituitary, which is a gland at the base of the brain that produces several hormones. The HESX1 protein is also necessary for the development of structures at the front of the brain (the forebrain), including the nerves that carry visual information from the eyes to the brain (optic nerves).

The HESX1 protein interacts with other proteins, including the protein produced from the PROP1 gene, during embryonic development. Both the HESX1 protein and the PROP1 protein bind to DNA and control the activity of other genes. The HESX1 protein turns off (represses) genes, while the PROP1 protein turns on (activates) genes. These proteins work together to coordinate the development of certain parts of the brain.

Does the HESX1 gene share characteristics with other genes?

The HESX1 gene belongs to a family of genes called homeobox (homeoboxes).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.

How are changes in the HESX1 gene related to health conditions?

septo-optic dysplasia - associated with the HESX1 gene

At least five mutations in the HESX1 gene have been identified in people with septo-optic dysplasia. Some of these mutations change single DNA building blocks (base pairs) in the HESX1 gene, while others insert or delete genetic material in the gene. Mutations in this gene alter the function of the HESX1 protein, for example by preventing it from binding to DNA and repressing the activity of other genes. HESX1 gene mutations disrupt the formation and early development of the pituitary gland, optic nerves, and other brain structures. These abnormalities of brain development lead to the characteristic features of septo-optic dysplasia.

Studies suggest that mutations in the HESX1 gene are a rare cause of septo-optic dysplasia.

other disorders - caused by mutations in the HESX1 gene

More than a dozen HESX1 gene mutations have been found to cause underdevelopment (hypoplasia) of the pituitary gland in people without the other characteristic features of septo-optic dysplasia. Pituitary hypoplasia leads to a shortage of hormones needed for growth, reproduction, and other critical body functions. Affected individuals may also have signs and symptoms affecting other parts of the body, including genital abnormalities, vision impairment, distinctive facial features, and extra (supernumerary) fingers.

Mutations in the HESX1 gene lead to the production of a defective or nonfunctional HESX1 protein, which disrupts the formation of the pituitary gland during critical stages of embryonic development. Some mutations prevent the HESX1 protein from binding to DNA and repressing the activity of other genes. Other mutations prevent the HESX1 protein from interacting with the PROP1 protein to coordinate brain development. It is unclear how mutations in the HESX1 gene can cause signs and symptoms affecting other parts of the body.

Genetics Home Reference provides information about combined pituitary hormone deficiency, which is also associated with changes in the HESX1 gene.

Where is the HESX1 gene located?

Cytogenetic Location: 3p14.3

Molecular Location on chromosome 3: base pairs 57,197,837 to 57,227,631

The HESX1 gene is located on the short (p) arm of chromosome 3 at position 14.3.

The HESX1 gene is located on the short (p) arm of chromosome 3 at position 14.3.

More precisely, the HESX1 gene is located from base pair 57,197,837 to base pair 57,227,631 on chromosome 3.

See How do geneticists indicate the location of a gene? in the Handbook.

Where can I find additional information about HESX1?

You and your healthcare professional may find the following resources about HESX1 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the HESX1 gene or gene products?

  • ANF
  • CPHD5
  • homeobox, ES cell expressed 1
  • Rathke pouch homeobox
  • RPX

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding HESX1?

cell ; deficiency ; DNA ; dysplasia ; embryonic ; expressed ; gene ; homeobox ; hormone ; hypoplasia ; pituitary gland ; protein ; reproduction ; transcription ; transcription factor

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

See also Understanding Medical Terminology.

References (11 links)


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.

Reviewed: March 2010
Published: September 28, 2015